completed README

README.md

@@ -1,3 +1,150 @@
 # chronos
 
 A Typst package to draw sequence diagrams with CeTZ
+
+---
+
+This package lets you render sequence diagrams directly in Typst. The following boilerplate code creates an empty sequence diagram with two participants:
+
+<table>
+<tr>
+<td><strong>Typst</strong></td>
+<td><strong>Result</strong></td>
+</tr>
+<tr>
+<td>
+
+```typst
+#import "@preview/chronos:0.1.0"
+#chronos.diagram({
+  import chronos: *
+  _par("Alice")
+  _par("Bob")
+})
+```
+
+</td>
+<td><img src="./gallery/readme/boilerplate.png"></td>
+</tr>
+</table>
+
+> *Disclaimer*\
+> The package cannot parse PlantUML syntax for the moment, and thus requires the use of element functions, as shown in the examples.
+> A PlantUML parser is in the TODO list, just not the top priority
+
+## Basic sequences
+
+You can make basic sequences using the `_seq` function:
+
+<table>
+<tr>
+<td><strong>Typst</strong></td>
+<td><strong>Result</strong></td>
+</tr>
+<tr>
+<td>
+
+```typst
+#chronos.diagram({
+  import chronos: *
+  _par("Alice")
+  _par("Bob")
+
+  _seq("Alice", "Bob", comment: "Hello")
+  _seq("Bob", "Bob", comment: "Think")
+  _seq("Bob", "Alice", comment: "Hi")
+})
+```
+
+</td>
+<td><img src="./gallery/readme/simple_sequence.png"></td>
+</tr>
+</table>
+
+You can make lifelines using the following parameters of the `_seq` function:
+ - `enable-dst`: enables the destination lifeline
+ - `create-dst`: creates the destination lifeline and participant
+ - `disable-dst`: disables the destination lifeline
+ - `destroy-dst`: destroys the destination lifeline and participant
+ - `disable-src`: disables the source lifeline
+ - `destroy-src`: destroy the source lifeline and participant
+
+<table>
+<tr>
+<td><strong>Typst</strong></td>
+<td><strong>Result</strong></td>
+</tr>
+<tr>
+<td>
+
+```typst
+#chronos.diagram({
+  import chronos: *
+  _par("A", display-name: "Alice")
+  _par("B", display-name: "Bob")
+  _par("C", display-name: "Charlie")
+  _par("D", display-name: "Derek")
+
+  _seq("A", "B", comment: "hello", enable-dst: true)
+  _seq("B", "B", comment: "self call", enable-dst: true)
+  _seq("C", "B", comment: "hello from thread 2", enable-dst: true, lifeline-style: (fill: rgb("#005500")))
+  _seq("B", "D", comment: "create", create-dst: true)
+  _seq("B", "C", comment: "done in thread 2", disable-src: true, dashed: true)
+  _seq("B", "B", comment: "rc", disable-src: true, dashed: true)
+  _seq("B", "D", comment: "delete", destroy-dst: true)
+  _seq("B", "A", comment: "success", disable-src: true, dashed: true)
+})
+```
+
+</td>
+<td><img src="./gallery/readme/lifelines.png"></td>
+</tr>
+</table>
+
+## Showcase
+
+Several features have already been implemented in Chronos. Don't hesitate to checkout the examples in the [gallery](./gallery) folder to see what you can do. 
+
+#### Quick example reference:
+<table>
+<tr>
+<td><strong>Example</strong></td>
+<td><strong>Features</strong></td>
+</tr>
+<tr>
+<td>
+
+`example1` <br>([PDF](./gallery/example1.pdf)|[Typst](./gallery/example1.typ))
+
+</td>
+<td>Simple cases, color sequences, groups, separators, gaps, self-sequences</td>
+</tr>
+<tr>
+<td>
+
+`example2` <br>([PDF](./gallery/example2.pdf)|[Typst](./gallery/example2.typ))
+
+</td>
+<td>Lifelines, found/lost messages, synchronized sequences, slanted sequences</td>
+</tr>
+<tr>
+<td>
+
+`example3` <br>([PDF](./gallery/example3.pdf)|[Typst](./gallery/example3.typ))
+
+</td>
+<td>Participant shapes, sequence tips, hidden partipicant ends</td>
+</tr>
+<tr>
+<td>
+
+`notes` <br>([PDF](./gallery/notes.pdf)|[Typst](./gallery/notes.typ))
+
+</td>
+<td>Notes (duh), deferred participant creation</td>
+</tr>
+</table>
+
+> [!NOTE]
+> 
+> Many examples were taken/adapted from the PlantUML [documentation](https://plantuml.com/sequence-diagram) on sequence diagrams

TODO.md

@@ -0,0 +1,27 @@
+# TODO
+
+- [x] Basic participants
+- [x] Basic sequences
+- [x] Separators
+- [x] Gaps
+- [x] Groups
+- [x] Self arrows
+- [x] Arrow from start / to end, small arrows
+- [x] Lifelines
+- [x] Different types of participants
+- [x] Notes
+- [x] Synchronized arrows
+- [x] Slanted arrows
+- [x] Different types of arrow tips
+- [x] Sequence comment alignment
+- [x] Fix group size with syncs
+- [ ] Fix column spacing with notes over multiple columns
+- [ ] Fix notes with arrows from start / to end / small arrows
+- [ ] Fix group size with self arrows + notes
+- [ ] Unify styling structure
+- [ ] Add args verification to catch user errors + pretty error messages
+- [ ] PlantUML parser
+- [ ] (Message numbering)
+- [ ] Different types of groups (alt/loop/etc.)
+- [ ] Delays
+- [ ] Auto-fit in parent

gallery.bash

@@ -0,0 +1,27 @@
+#!/bin/bash
+
+
+echo
+echo "Generating gallery PDFs"
+
+set -- ./gallery/*.typ
+cnt="$#"
+i=1
+for f
+do
+    f2="${f/typ/pdf}"
+    echo "($i/$cnt) $f -> $f2"
+    typst c --root ./ "$f" "$f2"
+    i=$((i+1))
+done
+
+set -- ./gallery/readme/*.typ
+cnt="$#"
+i=1
+for f
+do
+    f2="${f/typ/png}"
+    echo "($i/$cnt) $f -> $f2"
+    typst c --root ./ "$f" "$f2"
+    i=$((i+1))
+done

gallery/example1.typ

@@ -10,10 +10,65 @@ Alice <-- Bob: Another authentication Response
 
 
 #chronos.diagram({
-  import "/src/diagram.typ": *
+  import chronos: *
   _seq("Alice", "Bob", comment: "Authentication Request")
-  _seq("Bob", "Alice", comment: "Authentication Response", style: "dashed")
+  _seq("Bob", "Alice", comment: "Authentication Response", dashed: true)
   
   _seq("Alice", "Bob", comment: "Another authentication Request")
-  _seq("Bob", "Alice", comment: "Another authentication Response", style: "dashed")
+  _seq("Bob", "Alice", comment: "Another authentication Response", dashed: true)
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("Bob", "Alice", comment: "bonjour", color: red)
+  _seq("Alice", "Bob", comment: "ok", color: blue)
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("Alice", "Bob", comment: "This is a test")
+  _seq("Alice", "Callum", comment: "This is another test with a long text")
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("Alice", "Bob", comment: "Authentication Request")
+  _seq("Bob", "Alice", comment: "Authentication Failure")
+
+  _grp("My own label", desc: "My own label2", {
+    _seq("Alice", "Log", comment: "Log attack start")
+    _grp("loop", desc: "1000 times", {
+      _seq("Alice", "Bob", comment: "DNS Attack")
+    })
+    _seq("Alice", "Bob", comment: "Log attack end")
+  })
+})
+
+#chronos.diagram({
+  import chronos: *
+  _sep("Initialization")
+  _seq("Alice", "Bob", comment: "Authentication Request")
+  _seq("Bob", "Alice", comment: "Authentication Response", dashed: true)
+  
+  _sep("Repetition")
+  _seq("Alice", "Bob", comment: "Another authentication Request")
+  _seq("Bob", "Alice", comment: "another authentication Response", dashed: true)
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("Alice", "Bob", comment: "message 1")
+  _seq("Bob", "Alice", comment: "ok", dashed: true)
+  _gap()
+  _seq("Alice", "Bob", comment: "message 2")
+  _seq("Bob", "Alice", comment: "ok", dashed: true)
+  _gap(size: 45)
+  _seq("Alice", "Bob", comment: "message 3")
+  _seq("Bob", "Alice", comment: "ok", dashed: true)
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("Alice", "Alice", comment: "On the\nright")
+  _seq("Alice", "Alice", flip: true, comment: "On the\nleft")
 })

gallery/example2.typ

@@ -0,0 +1,169 @@
+#import "/src/lib.typ" as chronos
+
+
+#chronos.diagram({
+  import chronos: *
+  _seq("User", "A", comment: "DoWork", enable-dst: true)
+  _seq("A", "B", comment: [#sym.quote.angle.l createRequest #sym.quote.angle.r], enable-dst: true)
+  _seq("B", "C", comment: "DoWork", enable-dst: true)
+  _seq("C", "B", comment: "WorkDone", destroy-src: true, disable-src: true, dashed: true)
+  _seq("B", "A", comment: "RequestCreated", disable-src: true, dashed: true)
+  _seq("A", "User", comment: "Done", disable-src: true)
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("User", "A", comment: "DoWork", enable-dst: true, lifeline-style: (fill: rgb("#FFBBBB")))
+  _seq("A", "A", comment: "Internal call", enable-dst: true, lifeline-style: (fill: rgb("#E9967A")))
+  _seq("A", "B", comment: [#sym.quote.angle.l createRequest #sym.quote.angle.r], enable-dst: true)
+  _seq("B", "A", comment: "RequestCreated", disable-src: true, disable-dst: true, dashed: true)
+  _seq("A", "User", comment: "Done", disable-src: true)
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("alice", "bob", comment: "hello", enable-dst: true)
+  _seq("bob", "bob", comment: "self call", enable-dst: true)
+  _seq("bill", "bob", comment: "hello from thread 2", enable-dst: true, lifeline-style: (fill: rgb("#005500")))
+  _seq("bob", "george", comment: "create", create-dst: true)
+  _seq("bob", "bill", comment: "done in thread 2", disable-src: true, dashed: true)
+  _seq("bob", "bob", comment: "rc", disable-src: true, dashed: true)
+  _seq("bob", "george", comment: "delete", destroy-dst: true)
+  _seq("bob", "alice", comment: "success", disable-src: true, dashed: true)
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("alice", "bob", comment: "hello1", enable-dst: true)
+  _seq("bob", "charlie", comment: "hello2", enable-dst: true, disable-src: true)
+  _seq("charlie", "alice", comment: "ok", dashed: true, disable-src: true)
+})
+
+#chronos.diagram({
+  import chronos: *
+  _seq("?", "Alice", comment: [?->\ *short* to actor1])
+  _seq("[", "Alice", comment: [\[->\ *from start* to actor1])
+  _seq("[", "Bob", comment: [\[->\ *from start* to actor2])
+  _seq("?", "Bob", comment: [?->\ *short* to actor2])
+  _seq("Alice", "]", comment: [->\]\ from actor1 *to end*])
+  _seq("Alice", "?", comment: [->?\ *short* from actor1])
+  _seq("Alice", "Bob", comment: [->\ from actor1 to actor2])
+})
+
+#chronos.diagram({
+  import chronos: *
+  _par("alice", display-name: "Alice")
+  _par("bob", display-name: "Bob")
+  _par("craig", display-name: "Craig")
+
+  _seq("bob", "alice")
+  _seq("bob", "craig")
+  _gap()
+  
+  _sync({
+    _seq("bob", "alice", comment: "Synched", comment-align: "start")
+    _seq("bob", "craig", comment: "Synched", comment-align: "start")
+  })
+  _gap()
+  
+  _seq("alice", "bob")
+  _seq("craig", "bob")
+  _gap()
+  
+  _sync({
+    _seq("alice", "bob")
+    _seq("craig", "bob")
+  })
+  _gap()
+  
+  _sync({
+    _seq("alice", "bob", enable-dst: true)
+    _seq("craig", "bob")
+  })
+  _gap()
+
+  _evt("bob", "disable")
+})
+
+#chronos.diagram({
+  import chronos: *
+  _par("alice", display-name: "Alice")
+  _par("bob", display-name: "Bob")
+  _par("craig", display-name: "Craig")
+
+  _seq("alice", "bob")
+  _seq("bob", "craig", slant: auto)
+  _seq("alice", "craig", slant: 20)
+
+  _sync({
+    _seq("alice", "bob", slant: 10)
+    _seq("craig", "bob", slant: 20)
+  })
+
+  _sync({
+    _seq("alice", "bob", slant: auto)
+    _seq("bob", "alice", slant: auto)
+  })
+
+  _gap()
+  _evt("bob", "disable")
+})
+
+#grid(columns: 2, column-gutter: 2em,
+  chronos.diagram({
+    import chronos: *
+
+    _par("alice", display-name: "Alice")
+    _par("bob", display-name: "Bob")
+    _seq("alice", "bob", comment: "This is a very long comment")
+
+    // Left to right
+    _seq("alice", "bob", comment: "Start aligned", comment-align: "start")
+    _seq("alice", "bob", comment: "End aligned", comment-align: "end")
+    _seq("alice", "bob", comment: "Left aligned", comment-align: "left")
+    _seq("alice", "bob", comment: "Right aligned", comment-align: "right")
+    _seq("alice", "bob", comment: "Centered", comment-align: "center")
+    _gap()
+
+    // Right to left
+    _seq("bob", "alice", comment: "Start aligned", comment-align: "start")
+    _seq("bob", "alice", comment: "End aligned", comment-align: "end")
+    _seq("bob", "alice", comment: "Left aligned", comment-align: "left")
+    _seq("bob", "alice", comment: "Right aligned", comment-align: "right")
+    _seq("bob", "alice", comment: "Centered", comment-align: "center")
+    _gap()
+
+    // Slant left to right
+    _seq("alice", "bob", comment: "Start aligned", comment-align: "start", slant: 10)
+    _seq("alice", "bob", comment: "End aligned", comment-align: "end", slant: 10)
+    _seq("alice", "bob", comment: "Left aligned", comment-align: "left", slant: 10)
+    _seq("alice", "bob", comment: "Right aligned", comment-align: "right", slant: 10)
+    _seq("alice", "bob", comment: "Centered", comment-align: "center", slant: 10)
+    _gap()
+
+    // Slant right to left
+    _seq("bob", "alice", comment: "Start aligned", comment-align: "start", slant: 10)
+    _seq("bob", "alice", comment: "End aligned", comment-align: "end", slant: 10)
+    _seq("bob", "alice", comment: "Left aligned", comment-align: "left", slant: 10)
+    _seq("bob", "alice", comment: "Right aligned", comment-align: "right", slant: 10)
+    _seq("bob", "alice", comment: "Centered", comment-align: "center", slant: 10)
+  }),
+
+  chronos.diagram({
+    import chronos: *
+
+    _par("alice", display-name: "Alice")
+
+    _seq("alice", "alice", comment: "Start aligned", comment-align: "start")
+    _seq("alice", "alice", comment: "End aligned", comment-align: "end")
+    _seq("alice", "alice", comment: "Left aligned", comment-align: "left")
+    _seq("alice", "alice", comment: "Right aligned", comment-align: "right")
+    _seq("alice", "alice", comment: "Centered", comment-align: "center")
+
+    _seq("alice", "alice", comment: "Start aligned", comment-align: "start", flip: true)
+    _seq("alice", "alice", comment: "End aligned", comment-align: "end", flip: true)
+    _seq("alice", "alice", comment: "Left aligned", comment-align: "left", flip: true)
+    _seq("alice", "alice", comment: "Right aligned", comment-align: "right", flip: true)
+    _seq("alice", "alice", comment: "Centered", comment-align: "center", flip: true)
+  })
+)

gallery/example3.typ

@@ -0,0 +1,147 @@
+#import "/src/lib.typ" as chronos
+
+#set page(width: auto, height: auto)
+
+#let TYPST = image("typst.png", width: 1.5cm, height: 1.5cm, fit: "contain")
+#let FERRIS = image("ferris.png", width: 1.5cm, height: 1.5cm, fit: "contain")
+#let ME = image("me.jpg", width: 1.5cm, height: 1.5cm, fit: "contain")
+
+#chronos.diagram({
+  import chronos: *
+  _par("Foo", display-name: "Participant", shape: "participant")
+  _par("Foo1", display-name: "Actor", shape: "actor")
+  _par("Foo2", display-name: "Boundary", shape: "boundary")
+  _par("Foo3", display-name: "Control", shape: "control")
+  _par("Foo4", display-name: "Entity", shape: "entity")
+  _par("Foo5", display-name: "Database", shape: "database")
+  _par("Foo6", display-name: "Collections", shape: "collections")
+  _par("Foo7", display-name: "Queue", shape: "queue")
+  _par("Foo8", display-name: "Typst", shape: "custom", custom-image: TYPST)
+  _par("Foo9", display-name: "Ferris", shape: "custom", custom-image: FERRIS)
+  _par("Foo10", display-name: "Baryhobal", shape: "custom", custom-image: ME)
+
+  _seq("Foo", "Foo1", comment: "To actor")
+  _seq("Foo", "Foo2", comment: "To boundary")
+  _seq("Foo", "Foo3", comment: "To control")
+  _seq("Foo", "Foo4", comment: "To entity")
+  _seq("Foo", "Foo5", comment: "To database")
+  _seq("Foo", "Foo6", comment: "To collections")
+  _seq("Foo", "Foo7", comment: "To queue")
+  _seq("Foo", "Foo8", comment: "To Typst")
+  _seq("Foo", "Foo9", comment: "To ferris")
+  _seq("Foo", "Foo10", comment: "To Baryhobal")
+})
+
+#pagebreak()
+#chronos.diagram({
+  import chronos: *
+  _par("me", display-name: "Me", shape: "custom", custom-image: ME)
+  _par("typst", display-name: "Typst", shape: "custom", custom-image: TYPST)
+  _par("rust", display-name: "Rust", shape: "custom", custom-image: FERRIS)
+
+  _seq("me", "typst", comment: "opens document", enable-dst: true)
+  _seq("me", "typst", comment: "types document")
+  _seq("typst", "rust", comment: "compiles content", enable-dst: true)
+  _seq("rust", "typst", comment: "renders document", disable-src: true)
+  _seq("typst", "me", comment: "displays document")
+  _evt("typst", "disable")
+})
+
+#pagebreak()
+
+#stack(dir: ltr, spacing: 1em,
+chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _seq("a", "b", end-tip: ">", comment: `->`)
+  _seq("a", "b", end-tip: ">>", comment: `->>`)
+  _seq("a", "b", end-tip: "\\", comment: `-\`)
+  _seq("a", "b", end-tip: "\\\\", comment: `-\\`)
+  _seq("a", "b", end-tip: "/", comment: `-/`)
+  _seq("a", "b", end-tip: "//", comment: `-//`)
+  _seq("a", "b", end-tip: "x", comment: `->x`)
+  _seq("a", "b", start-tip: "x", comment: `x->`)
+  _seq("a", "b", start-tip: "o", comment: `o->`)
+  _seq("a", "b", end-tip: ("o", ">"), comment: `->o`)
+  _seq("a", "b", start-tip: "o", end-tip: ("o", ">"), comment: `o->o`)
+  _seq("a", "b", start-tip: ">", end-tip: ">", comment: `<->`)
+  _seq("a", "b", start-tip: ("o", ">"), end-tip: ("o", ">"), comment: `o<->o`)
+  _seq("a", "b", start-tip: "x", end-tip: "x", comment: `x<->x`)
+  _seq("a", "b", end-tip: ("o", ">>"), comment: `->>o`)
+  _seq("a", "b", end-tip: ("o", "\\"), comment: `-\o`)
+  _seq("a", "b", end-tip: ("o", "\\\\"), comment: `-\\o`)
+  _seq("a", "b", end-tip: ("o", "/"), comment: `-/o`)
+  _seq("a", "b", end-tip: ("o", "//"), comment: `-//o`)
+  _seq("a", "b", start-tip: "x", end-tip: ("o", ">"), comment: `x->o`)
+}),
+
+chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _seq("b", "a", end-tip: ">", comment: `->`)
+  _seq("b", "a", end-tip: ">>", comment: `->>`)
+  _seq("b", "a", end-tip: "\\", comment: `-\`)
+  _seq("b", "a", end-tip: "\\\\", comment: `-\\`)
+  _seq("b", "a", end-tip: "/", comment: `-/`)
+  _seq("b", "a", end-tip: "//", comment: `-//`)
+  _seq("b", "a", end-tip: "x", comment: `->x`)
+  _seq("b", "a", start-tip: "x", comment: `x->`)
+  _seq("b", "a", start-tip: "o", comment: `o->`)
+  _seq("b", "a", end-tip: ("o", ">"), comment: `->o`)
+  _seq("b", "a", start-tip: "o", end-tip: ("o", ">"), comment: `o->o`)
+  _seq("b", "a", start-tip: ">", end-tip: ">", comment: `<->`)
+  _seq("b", "a", start-tip: ("o", ">"), end-tip: ("o", ">"), comment: `o<->o`)
+  _seq("b", "a", start-tip: "x", end-tip: "x", comment: `x<->x`)
+  _seq("b", "a", end-tip: ("o", ">>"), comment: `->>o`)
+  _seq("b", "a", end-tip: ("o", "\\"), comment: `-\o`)
+  _seq("b", "a", end-tip: ("o", "\\\\"), comment: `-\\o`)
+  _seq("b", "a", end-tip: ("o", "/"), comment: `-/o`)
+  _seq("b", "a", end-tip: ("o", "//"), comment: `-//o`)
+  _seq("b", "a", start-tip: "x", end-tip: ("o", ">"), comment: `x->o`)
+}),
+
+chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _seq("a", "a", end-tip: ">", comment: `->`)
+  _seq("a", "a", end-tip: ">>", comment: `->>`)
+  _seq("a", "a", end-tip: "\\", comment: `-\`)
+  _seq("a", "a", end-tip: "\\\\", comment: `-\\`)
+  _seq("a", "a", end-tip: "/", comment: `-/`)
+  _seq("a", "a", end-tip: "//", comment: `-//`)
+  _seq("a", "a", end-tip: "x", comment: `->x`)
+  _seq("a", "a", start-tip: "x", comment: `x->`)
+  _seq("a", "a", start-tip: "o", comment: `o->`)
+  _seq("a", "a", end-tip: ("o", ">"), comment: `->o`)
+  _seq("a", "a", start-tip: "o", end-tip: ("o", ">"), comment: `o->o`)
+  _seq("a", "a", start-tip: ">", end-tip: ">", comment: `<->`)
+  _seq("a", "a", start-tip: ("o", ">"), end-tip: ("o", ">"), comment: `o<->o`)
+  _seq("a", "a", start-tip: "x", end-tip: "x", comment: `x<->x`)
+  _seq("a", "a", end-tip: ("o", ">>"), comment: `->>o`)
+  _seq("a", "a", end-tip: ("o", "\\"), comment: `-\o`)
+  _seq("a", "a", end-tip: ("o", "\\\\"), comment: `-\\o`)
+  _seq("a", "a", end-tip: ("o", "/"), comment: `-/o`)
+  _seq("a", "a", end-tip: ("o", "//"), comment: `-//o`)
+  _seq("a", "a", start-tip: "x", end-tip: ("o", ">"), comment: `x->o`)
+})
+)
+
+#chronos.diagram({
+  import chronos: *
+
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob", show-bottom: false)
+  _par("c", display-name: "Caleb", show-top: false)
+  _par("d", display-name: "Danny", show-bottom: false, show-top: false)
+
+  _gap()
+})

gallery/notes.typ

@@ -0,0 +1,145 @@
+#import "/src/lib.typ" as chronos: *
+
+#set page(width: auto, height: auto)
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _seq("a", "b", comment: [hello])
+  _note("left", [this is a first note])
+
+  _seq("b", "a", comment: [ok])
+  _note("right", [this is another note])
+
+  _seq("b", "b", comment: [I am thinking])
+  _note("left", [a note\ can also be defined\ on several lines])
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _note("left", [This is displayed\ left of Alice.], pos: "a", color: rgb("#00FFFF"))
+  _note("right", [This is displayed right of Alice.], pos: "a")
+  _note("over", [This is displayed over Alice.], pos: "a")
+  _note("over", [This is displayed\ over Bob and Alice.], pos: ("a", "b"), color: rgb("#FFAAAA"))
+  _note("over", [This is yet another\ example of\ a long note.], pos: ("a", "b"))
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("caller")
+  _par("server")
+
+  _seq("caller", "server", comment: [conReq])
+  _note("over", [idle], pos: "caller", shape: "hex")
+  _seq("server", "caller", comment: [conConf])
+  _note("over", ["r" as rectangle\ "h" as hexagon], pos: "server", shape: "rect")
+  _note("over", [this is\ on several\ lines], pos: "server", shape: "rect")
+  _note("over", [this is\ on several\ lines], pos: "caller", shape: "hex")
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+  _par("c", display-name: "Charlie")
+
+  _seq("a", "b", comment: [m1])
+  _seq("b", "c", comment: [m2])
+
+  _note("over", [Old method for note over all part. with:\ `note over FirstPart, LastPart`.], pos: ("a", "c"))
+  _note("across", [New method with:\ `note across`.])
+
+  _seq("b", "a")
+
+  _note("across", [Note across all part.], shape: "hex")
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+
+  _note("over", [initial state of Alice], pos: "a")
+  _note("over", [initial state of Bob], pos: "b")
+  _seq("b", "a", comment: [hello])
+})
+
+#chronos.diagram({
+  _par("a", display-name: "Alice")
+  _par("b", display-name: "Bob")
+  _par("c", display-name: "Charlie")
+  _par("d", display-name: "Donald")
+  _par("e", display-name: "Eddie")
+
+  _note("over", [initial state of Alice], pos: "a")
+  _note("over", [initial state of Bob the builder], pos: "b", aligned: true)
+
+  _note("over", [Note 1], pos: "a")
+  _note("over", [Note 2], pos: "b", aligned: true)
+  _note("over", [Note 3], pos: "c", aligned: true)
+
+  _seq("a", "d")
+  _note("over", [this is an extremely long note], pos: ("d", "e"))
+})
+
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: [Alice])
+  _par("b", display-name: [The *Famous* Bob])
+
+  _seq("a", "b", comment: [hello #strike([there])])
+
+  _gap()
+  _seq("b", "a", comment: [ok])
+  _note("left", [
+    This is *bold*\
+    This is _italics_\
+    This is `monospaced`\
+    This is #strike([stroked])\
+    This is #underline([underlined])\
+    This is #underline([waved])\
+  ])
+
+  _seq("a", "b", comment: [A _well formatted_ message])
+  _note("right", [
+    This is #box(text([displayed], size: 18pt), fill: rgb("#5F9EA0"))\
+    #underline([left of]) Alice.
+  ], pos: "a")
+  _note("left", [
+    #underline([This], stroke: red) is #text([displayed], fill: rgb("#118888"))\
+    *#text([left of], fill: rgb("#800080")) #strike([Alice], stroke: red) Bob.*
+  ], pos: "b")
+  _note("over", [
+    #underline([This is hosted], stroke: rgb("#FF33FF")) by #box(baseline: 50%, image("gitea.png", width: 1cm, height: 1cm, fit: "contain"))
+  ], pos: ("a", "b"))
+})
+
+// TODO
+/*
+#pagebreak()
+
+#chronos.diagram({
+  _par("a", display-name: [Alice])
+  _par("b", display-name: [Bob])
+
+  _seq("a", "b", comment: [Hello])
+  _note("left", [This is a note])
+
+  _seq("[", "a", comment: [Test])
+  _note("left", [This is also a note])
+})*/
+
+#pagebreak()
+
+#chronos.diagram({
+  _seq("Bob", "Alice", comment: [Hello])
+  _evt("Other", "create")
+})

gallery/readme/boilerplate.typ

@@ -0,0 +1,13 @@
+#import "/src/lib.typ" as chronos
+
+#set page(
+  width: auto,
+  height: auto,
+  margin: 0.5cm
+)
+
+#chronos.diagram({
+  import chronos: *
+  _par("Alice")
+  _par("Bob")
+})

gallery/readme/lifelines.typ

@@ -0,0 +1,24 @@
+#import "/src/lib.typ" as chronos
+
+#set page(
+  width: auto,
+  height: auto,
+  margin: 0.5cm
+)
+
+#chronos.diagram({
+  import chronos: *
+  _par("A", display-name: "Alice")
+  _par("B", display-name: "Bob")
+  _par("C", display-name: "Charlie")
+  _par("D", display-name: "Derek")
+
+  _seq("A", "B", comment: "hello", enable-dst: true)
+  _seq("B", "B", comment: "self call", enable-dst: true)
+  _seq("C", "B", comment: "hello from thread 2", enable-dst: true, lifeline-style: (fill: rgb("#005500")))
+  _seq("B", "D", comment: "create", create-dst: true)
+  _seq("B", "C", comment: "done in thread 2", disable-src: true, dashed: true)
+  _seq("B", "B", comment: "rc", disable-src: true, dashed: true)
+  _seq("B", "D", comment: "delete", destroy-dst: true)
+  _seq("B", "A", comment: "success", disable-src: true, dashed: true)
+})

gallery/readme/simple_sequence.typ

@@ -0,0 +1,17 @@
+#import "/src/lib.typ" as chronos
+
+#set page(
+  width: auto,
+  height: auto,
+  margin: 0.5cm
+)
+
+#chronos.diagram({
+  import chronos: *
+  _par("Alice")
+  _par("Bob")
+
+  _seq("Alice", "Bob", comment: "Hello")
+  _seq("Bob", "Bob", comment: "Think")
+  _seq("Bob", "Alice", comment: "Hi")
+})

src/consts.typ

@@ -0,0 +1,30 @@
+#let Y-SPACE = 10
+#let PAR-SPACE = 10
+#let COMMENT-PAD = 8
+#let LIFELINE-W = 10
+#let CREATE-OFFSET = 15
+#let DEFAULT-SLANT = 10
+#let CROSS-TIP-SIZE = 4
+#let CIRCLE-TIP-RADIUS = 3
+
+#let SYM-GAP = 5
+#let PAR-PAD = (5pt, 3pt)
+#let ACTOR-WIDTH = 20
+#let BOUNDARY-HEIGHT = 20
+#let CONTROL-HEIGHT = 20
+#let ENTITY-HEIGHT = 20
+#let DATABASE-WIDTH = 24
+#let COLLECTIONS-PAD = (5pt, 3pt)
+#let COLLECTIONS-DX = 3
+#let COLLECTIONS-DY = 3
+#let QUEUE-PAD = (5pt, 3pt)
+
+#let NOTE-PAD = (6, 3)
+#let NOTE-CORNER-SIZE = 6
+#let NOTE-GAP = 3
+#let NOTE-HEX-PAD = (6, 8)
+
+#let COL-DESTRUCTION = rgb("#A80238")
+#let COL-GRP-NAME = rgb("#EEEEEE")
+#let COL-SEP-NAME = rgb("#EEEEEE")
+#let COL-NOTE = rgb("#FEFFDD")

src/diagram.typ

@@ -1,49 +1,195 @@
+#import "utils.typ": get-group-span, fit-canvas
 #import "renderer.typ": render
+#import "participant.typ" as participant: _par, PAR-SPECIALS
 
-#let _seq(p1, p2, comment: none, style: auto) = {
+#let _gap(size: 20) = {
   return ((
-    type: "seq",
+    type: "gap",
-    p1: p1,
+    size: size
-    p2: p2,
-    comment: comment,
-    style: style
   ),)
 }
 
-#let _par(name, display-name: auto, start-at: 0) = {
+#let _evt(participant, event) = {
   return ((
-    type: "par",
+    type: "evt",
-    name: name,
+    participant: participant,
-    display-name: if display-name == auto {name} else {display-name},
+    event: event,
-    start-at: start-at
+    lifeline-style: auto
   ),)
 }
 
-#let _par-exists(participants, name) = {
+#let diagram(elements, width: auto) = {
-  for p in participants {
+  if elements == none {
-    if name == p.name {
+    return
-      return true
-    }
   }
-  return false
-}
   
-#let diagram(elements) = {
   let participants = ()
-  for elmt in elements {
+  let elmts = elements
+  let i = 0
+
+  // Flatten groups
+  while i < elmts.len() {
+    let elmt = elmts.at(i)
+    if elmt.type == "grp" {
+      let grp-elmts = elmt.elmts
+      elmt.elmts = elmt.elmts.map(e => {
+        if e.type == "seq" {
+          if e.p1 == "?" {
+            e.p1 = "?" + e.p2
+          } else if e.p2 == "?" {
+            e.p2 = e.p1 + "?"
+          }
+        }
+        e
+      })
+      elmts.at(i) = elmt
+      elmts = (
+        elmts.slice(0, i + 1) +
+        grp-elmts +
+        ((
+          type: "grp-end"
+        ),) +
+        elmts.slice(i+1)
+      )
+    }
+    i += 1
+  }
+
+  // List participants
+  let linked = ()
+  let last-seq = none
+  let last-note = none
+  for (i, elmt) in elmts.enumerate() {
     if elmt.type == "par" {
       participants.push(elmt)
     } else if elmt.type == "seq" {
-      if not _par-exists(participants, elmt.p1) {
+      if not participant._exists(participants, elmt.p1) {
         participants.push(_par(elmt.p1).first())
       }
-      if not _par-exists(participants, elmt.p2) {
+      if not participant._exists(participants, elmt.p2) {
-        participants.push(_par(elmt.p2).first())
+        let par = _par(elmt.p2, from-start: not elmt.create-dst).first()
+        participants.push(par)
+      
+      } else if elmt.create-dst {
+        let i = participants.position(p => p.name == elmt.p2)
+        participants.at(i).from-start = false
+      }
+
+      let p1 = elmt.p1
+      let p2 = elmt.p2
+      if elmt.p1 == "?" {
+        p1 = "?" + elmt.p2
+      }
+      if elmt.p2 == "?" {
+        p2 = elmt.p1 + "?"
+      }
+      linked.push(p1)
+      linked.push(p2)
+      last-seq = (
+        elmt: elmt,
+        i: i,
+        p1: p1,
+        p2: p2
+      )
+    } else if elmt.type == "note" {
+      elmt.insert("linked", elmt.pos == none and elmt.side != "across")
+      if elmt.pos == none and elmt.side != "across" {
+        let names = participants.map(p => p.name)
+        let i1 = names.position(n => n == last-seq.p1)
+        let i2 = names.position(n => n == last-seq.p2)
+        let pars = ((i1, last-seq.p1), (i2, last-seq.p2)).sorted(key: p => p.first())
+        if elmt.side == "left" {
+          elmt.pos = pars.first().last()
+        } else if elmt.side == "right" {
+          elmt.pos = pars.last().last()
+        }
+
+        let seq = last-seq.elmt
+        seq.insert("linked-note", elmt)
+        elmts.at(last-seq.i) = seq
+      }
+      if elmt.aligned {
+        let n = last-note.elmt
+        n.aligned-with = elmt
+        elmts.at(last-note.i) = n
+      }
+      elmts.at(i) = elmt
+      if elmt.side == "left" {
+        linked.push("[")
+      } else if elmt.side == "right" {
+        linked.push("]")
+      }
+      last-note = (
+        elmt: elmt,
+        i: i
+      )
+    } else if elmt.type == "evt" {
+      let par = elmt.participant
+      if not participant._exists(participants, par) {
+        let p = _par(par, from-start: elmt.event != "create").first()
+        participants.push(p)
+      
+      } else if elmt.event == "create" {
+        let i = participants.position(p => p.name == par)
+        participants.at(i).from-start = false
+      }
+    }
+  }
+  linked = linked.dedup()
+
+  let pars = participants
+  participants = ()
+  
+  if "[" in linked {
+    participants.push(_par("[", invisible: true).first())
+  }
+  
+  for (i, p) in pars.enumerate() {
+    let before = _par("?" + p.name, invisible: true).first()
+    let after = _par(p.name + "?", invisible: true).first()
+    
+    if before.name in linked {
+      if participants.len() == 0 or not participants.last().name.ends-with("?") {
+        participants.push(before)
+      } else {
+        participants.insert(-1, before)
+      }
+    }
+
+    participants.push(p)
+
+    if after.name in linked {
+      participants.push(after)
+    }
+  }
+  if "]" in linked {
+    participants.push(_par("]", invisible: true).first())
+  }
+
+  // Add index to participant
+  for (i, p) in participants.enumerate() {
+    p.insert("i", i)
+    participants.at(i) = p
+  }
+
+  // Compute groups spans (horizontal)
+  for (i, elmt) in elmts.enumerate() {
+    if elmt.type == "grp" {
+      let (min-i, max-i) = get-group-span(participants, elmt)
+      elmts.at(i).insert("min-i", min-i)
+      elmts.at(i).insert("max-i", max-i)
+    } else if elmt.type == "seq" {
+      if elmt.p1 == "?" {
+        elmts.at(i).p1 = "?" + elmt.p2
+      } else if elmt.p2 == "?" {
+        elmts.at(i).p2 = elmt.p1 + "?"
       }
     }
   }
 
-  render(participants, elements)
+  set text(font: "Source Sans 3")
+  let canvas = render(participants, elmts)
+  fit-canvas(canvas, width: width)
 }
 
 #let from-plantuml(code) = {

src/group.typ

@@ -0,0 +1,54 @@
+#import "@preview/cetz:0.2.2": draw
+#import "consts.typ": *
+
+#let _grp(name, desc: none, type: "default", elmts) = {
+  return ((
+    type: "grp",
+    name: name,
+    desc: desc,
+    grp-type: type,
+    elmts: elmts
+  ),)
+}
+
+#let render(x0, x1, y0, y1, group) = {
+  let shapes = ()
+  let name = text(group.name, weight: "bold")
+  let m = measure(box(name))
+  let w = m.width / 1pt + 15
+  let h = m.height / 1pt + 6
+  shapes += draw.rect(
+    (x0, y0),
+    (x1, y1)
+  )
+  shapes += draw.merge-path(
+    fill: COL-GRP-NAME,
+    close: true,
+    {
+      draw.line(
+        (x0, y0),
+        (x0 + w, y0),
+        (x0 + w, y0 - h / 2),
+        (x0 + w - 5, y0 - h),
+        (x0, y0 - h)
+      )
+    }
+  )
+  shapes += draw.content(
+    (x0, y0),
+    name,
+    anchor: "north-west",
+    padding: (left: 5pt, right: 10pt, top: 3pt, bottom: 3pt)
+  )
+
+  if group.desc != none {
+    shapes += draw.content(
+      (x0 + w, y0),
+      text([\[#group.desc\]], weight: "bold", size: .8em),
+      anchor: "north-west",
+      padding: 3pt
+    )
+  }
+
+  return shapes
+}

src/lib.typ

@@ -1 +1,8 @@
-#import "diagram.typ": diagram, from-plantuml
+#import "diagram.typ": diagram, from-plantuml, _gap, _evt
+
+#import "sequence.typ": _seq
+#import "group.typ": _grp
+#import "participant.typ": _par
+#import "separator.typ": _sep
+#import "note.typ": _note
+#import "sync.typ": _sync

src/note.typ

@@ -0,0 +1,182 @@
+#import "@preview/cetz:0.2.2": draw
+#import "consts.typ": *
+
+#let SIDES = (
+  "left",
+  "right",
+  "over",
+  "across"
+)
+
+#let SHAPES = (
+  "default",
+  "rect",
+  "hex"
+)
+
+#let _note(side, content, pos: none, color: COL-NOTE, shape: "default", aligned: false) = {
+  if side == "over" {
+    if pos == none {
+      panic("Pos cannot be none with side 'over'")
+    }
+  }
+  if aligned {
+    if side != "over" {
+      panic("Aligned notes can only be over a participant (got side '" + side + "')")
+    }
+  }
+  return ((
+    type: "note",
+    side: side,
+    content: content,
+    pos: pos,
+    color: color,
+    shape: shape,
+    aligned: aligned,
+    aligned-with: none
+  ),)
+}
+
+#let get-note-box(note) = {
+  let PAD = if note.shape == "hex" {NOTE-HEX-PAD} else {NOTE-PAD}
+  let inset = (
+    left: PAD.last() * 1pt,
+    right: PAD.last() * 1pt,
+    top: PAD.first() * 1pt,
+    bottom: PAD.first() * 1pt,
+  )
+  if note.shape == "default" {
+    inset.right += NOTE-CORNER-SIZE * 1pt
+  }
+  if note.side == "left" {
+    inset.right += NOTE-GAP * 1pt
+  } else if note.side == "right" {
+    inset.left += NOTE-GAP * 1pt
+  }
+  return box(note.content, inset: inset)
+}
+
+#let get-size(note) = {
+  let PAD = if note.shape == "hex" {NOTE-HEX-PAD} else {NOTE-PAD}
+  let m = measure(box(note.content))
+  let w = m.width / 1pt + PAD.last() * 2
+  let h = m.height / 1pt + PAD.first() * 2
+  if note.shape == "default" {
+    w += NOTE-CORNER-SIZE
+  }
+  return (
+    width: w,
+    height: h
+  )
+}
+
+#let _get-base-x(pars-i, x-pos, note) = {
+  if note.side == "across" {
+    return (x-pos.first() + x-pos.last()) / 2
+  }
+  if note.side == "over" {
+    if type(note.pos) == array {
+      let xs = note.pos.map(par => x-pos.at(pars-i.at(par)))
+      return (calc.min(..xs) + calc.max(..xs)) / 2
+    }
+  }
+  return x-pos.at(pars-i.at(note.pos))
+}
+
+#let render(pars-i, x-pos, note, y, lifelines) = {
+  let shapes = ()
+  let PAD = if note.shape == "hex" {NOTE-HEX-PAD} else {NOTE-PAD}
+  let m = measure(box(note.content))
+  let w = m.width / 1pt + PAD.last() * 2
+  let h = m.height / 1pt + PAD.first() * 2
+  let total-w = w
+  if note.shape == "default" {
+    total-w += NOTE-CORNER-SIZE
+  }
+
+  let base-x = _get-base-x(pars-i, x-pos, note)
+
+  let i = none
+  if note.pos != none and type(note.pos) == str {
+    i = pars-i.at(note.pos)
+  }
+  let x0 = base-x
+  if note.side == "left" {
+    x0 -= NOTE-GAP
+    x0 -= total-w
+    if lifelines.at(i).level != 0 {
+      x0 -= LIFELINE-W / 2
+    }
+  } else if note.side == "right" {
+    x0 += NOTE-GAP
+    x0 += lifelines.at(i).level * LIFELINE-W / 2
+  } else if note.side == "over" or note.side == "across" {
+    x0 -= total-w / 2
+  }
+
+  let x1 = x0 + w
+  let x2 = x0 + total-w
+  let y0 = y
+
+  if note.linked {
+    y0 += h / 2
+  }
+  let y1 = y0 - h
+
+  if note.shape == "default" {
+    shapes += draw.merge-path(
+      stroke: black + .5pt,
+      fill: note.color,
+      close: true,
+      {
+        draw.line(
+          (x0, y0),
+          (x1, y0),
+          (x2, y0 - NOTE-CORNER-SIZE),
+          (x2, y1),
+          (x0, y1)
+        )
+      }
+    )
+    shapes += draw.line((x1, y0), (x1, y0 - NOTE-CORNER-SIZE), (x2, y0 - NOTE-CORNER-SIZE), stroke: black + .5pt)
+  } else if note.shape == "rect" {
+    shapes += draw.rect(
+      (x0, y0),
+      (x2, y1),
+      stroke: black + .5pt,
+      fill: note.color
+    )
+  } else if note.shape == "hex" {
+    let lx = x0 + PAD.last()
+    let rx = x2 - PAD.last()
+    let my = (y0 + y1) / 2
+    shapes += draw.merge-path(
+      stroke: black + .5pt,
+      fill: note.color,
+      close: true,
+      {
+        draw.line(
+          (lx, y0),
+          (rx, y0),
+          (x2, my),
+          (rx, y1),
+          (lx, y1),
+          (x0, my),
+        )
+      }
+    )
+  }
+
+  shapes += draw.content(
+    ((x0 + x1)/2, (y0 + y1)/2),
+    note.content,
+    anchor: "center"
+  )
+
+  if note.aligned-with == none and (note.pos != none or note.side == "across") {
+    y -= h
+  }
+
+  let r = (y, shapes)
+  return r
+}

src/participant.typ

@@ -0,0 +1,357 @@
+#import "@preview/cetz:0.2.2": draw
+#import "consts.typ": *
+
+#let PAR-SPECIALS = "?[]"
+#let SHAPES = (
+  "participant",
+  "actor",
+  "boundary",
+  "control",
+  "entity",
+  "database",
+  "collections",
+  "queue",
+  "custom"
+)
+
+#let _par(
+  name,
+  display-name: auto,
+  from-start: true,
+  invisible: false,
+  shape: "participant",
+  color: rgb("#E2E2F0"),
+  custom-image: none,
+  show-bottom: true,
+  show-top: true,
+) = {
+  return ((
+    type: "par",
+    name: name,
+    display-name: if display-name == auto {name} else {display-name},
+    from-start: from-start,
+    invisible: invisible,
+    shape: shape,
+    color: color,
+    custom-image: custom-image,
+    show-bottom: show-bottom,
+    show-top: show-top
+  ),)
+}
+
+#let _exists(participants, name) = {
+  if name == "?" or name == "[" or name == "]" {
+    return true
+  }
+
+  for p in participants {
+    if name == p.name {
+      return true
+    }
+  }
+  return false
+}
+
+#let get-size(par) = {
+  if par.invisible {
+    return (width: 0pt, height: 0pt)
+  }
+  let m = measure(box(par.display-name))
+  let w = m.width
+  let h = m.height
+  let (shape-w, shape-h) = (
+    participant: (w + PAR-PAD.last() * 2, h + PAR-PAD.first() * 2),
+    actor: (ACTOR-WIDTH * 1pt, ACTOR-WIDTH * 2pt + SYM-GAP * 1pt + h),
+    boundary: (BOUNDARY-HEIGHT * 2pt, BOUNDARY-HEIGHT * 1pt + SYM-GAP * 1pt + h),
+    control: (CONTROL-HEIGHT * 1pt, CONTROL-HEIGHT * 1pt + SYM-GAP * 1pt + h),
+    entity: (ENTITY-HEIGHT * 1pt, ENTITY-HEIGHT * 1pt + 2pt + SYM-GAP * 1pt + h),
+    database: (DATABASE-WIDTH * 1pt, DATABASE-WIDTH * 4pt / 3 + SYM-GAP * 1pt + h),
+    collections: (
+      w + COLLECTIONS-PAD.last() * 2 + calc.abs(COLLECTIONS-DX) * 1pt,
+      h + COLLECTIONS-PAD.first() * 2 + calc.abs(COLLECTIONS-DY) * 1pt,
+    ),
+    queue: (
+      w + QUEUE-PAD.last() * 2 + 3 * (h + QUEUE-PAD.first() * 2) / 4,
+      h + QUEUE-PAD.first() * 2
+    ),
+    custom: (
+      measure(par.custom-image).width,
+      measure(par.custom-image).height + SYM-GAP * 1pt + h
+    )
+  ).at(par.shape)
+
+  return (
+    width: calc.max(w, shape-w),
+    height: calc.max(h, shape-h)
+  )
+}
+
+#let _render-participant(x, y, p, m, bottom) = {
+  let w = m.width / 1pt
+  let h = m.height / 1pt
+  let x0 = x - w / 2 - PAR-PAD.last() / 1pt
+  let x1 = x + w / 2 + PAR-PAD.last() / 1pt
+  let y0 = y + h + PAR-PAD.first() / 1pt * 2
+  if bottom {
+    y0 = y
+  }
+  let y1 = y0 - h - PAR-PAD.first() / 1pt * 2
+
+  draw.rect(
+    (x0, y0),
+    (x1, y1),
+    radius: 2pt,
+    fill: p.color,
+    stroke: black + .5pt
+  )
+  draw.content(
+    ((x0 + x1) / 2, (y0 + y1) / 2),
+    p.display-name,
+    anchor: "center"
+  )
+}
+
+#let _render-actor(x, y, p, m, bottom) = {
+  let w2 = ACTOR-WIDTH / 2
+  let head-r = ACTOR-WIDTH / 4
+  let height = ACTOR-WIDTH * 2
+  let arms-y = height * 0.375
+
+  let y0 = if bottom {y - m.height / 1pt - SYM-GAP} else {y + m.height / 1pt + height + SYM-GAP}
+  draw.circle(
+    (x, y0 - head-r),
+    radius: head-r,
+    fill: p.color,
+    stroke: black + .5pt
+  )
+  draw.line((x, y0 - head-r * 2), (x, y0 - height + w2), stroke: black + .5pt)
+  draw.line((x - w2, y0 - arms-y), (x + w2, y0 - arms-y), stroke: black + .5pt)
+  draw.line((x - w2, y0 - height), (x, y0 - height + w2), (x + w2, y0 - height), stroke: black + .5pt)
+  draw.content(
+    (x, y),
+    p.display-name,
+    anchor: if bottom {"north"} else {"south"}
+  )
+}
+
+#let _render-boundary(x, y, p, m, bottom) = {
+  let circle-r = BOUNDARY-HEIGHT / 2
+  let y0 = if bottom {y - m.height / 1pt - SYM-GAP} else {y + m.height / 1pt + BOUNDARY-HEIGHT + SYM-GAP}
+  let x0 = x - BOUNDARY-HEIGHT
+  let y1 = y0 - circle-r
+  let y2 = y0 - BOUNDARY-HEIGHT
+
+  draw.circle(
+    (x + circle-r, y1),
+    radius: circle-r,
+    fill: p.color,
+    stroke: black + .5pt
+  )
+  draw.line(
+    (x0, y0), (x0, y2),
+    stroke: black + .5pt
+  )
+  draw.line(
+    (x0, y1), (x, y1),
+    stroke: black + .5pt
+  )
+  draw.content(
+    (x, y),
+    p.display-name,
+    anchor: if bottom {"north"} else {"south"}
+  )
+}
+
+#let _render-control(x, y, p, m, bottom) = {
+  let r = CONTROL-HEIGHT / 2
+  let y0 = if bottom {y - m.height / 1pt - SYM-GAP} else {y + m.height / 1pt + CONTROL-HEIGHT + SYM-GAP}
+
+  draw.circle(
+    (x, y0 - r),
+    radius: r,
+    fill: p.color,
+    stroke: black + .5pt
+  )
+  draw.mark((x, y0), (x - r / 2, y0), symbol: "stealth", fill: black)
+  draw.content(
+    (x, y),
+    p.display-name,
+    anchor: if bottom {"north"} else {"south"}
+  )
+}
+
+#let _render-entity(x, y, p, m, bottom) = {
+  let r = ENTITY-HEIGHT / 2
+  let y0 = if bottom {y - m.height / 1pt - SYM-GAP} else {y + m.height / 1pt + ENTITY-HEIGHT + SYM-GAP}
+  let y1 = y0 - ENTITY-HEIGHT - 1.5
+
+  draw.circle(
+    (x, y0 - r),
+    radius: r,
+    fill: p.color,
+    stroke: black + .5pt
+  )
+  draw.line(
+    (x - r, y1),
+    (x + r, y1),
+    stroke: black + .5pt
+  )
+  draw.content(
+    (x, y),
+    p.display-name,
+    anchor: if bottom {"north"} else {"south"}
+  )
+}
+
+#let _render-database(x, y, p, m, bottom) = {
+  let height = DATABASE-WIDTH * 4 / 3
+  let rx = DATABASE-WIDTH / 2
+  let ry = rx / 2
+  let y0 = if bottom {y - m.height / 1pt - SYM-GAP} else {y + m.height / 1pt + height + SYM-GAP}
+  let y1 = y0 - height
+
+  draw.merge-path(
+    close: true,
+    fill: p.color,
+    stroke: black + .5pt,
+    {
+      draw.bezier((x - rx, y0 - ry), (x, y0), (x - rx, y0 - ry/2), (x - rx/2, y0))
+      draw.bezier((), (x + rx, y0 - ry), (x + rx/2, y0), (x + rx, y0 - ry/2))
+      draw.line((), (x + rx, y1 + ry))
+      draw.bezier((), (x, y1), (x + rx, y1 + ry/2), (x + rx/2, y1))
+      draw.bezier((), (x - rx, y1 + ry), (x - rx/2, y1), (x - rx, y1 + ry/2))
+    }
+  )
+  draw.merge-path(
+    stroke: black + .5pt,
+    {
+      draw.bezier((x - rx, y0 - ry), (x, y0 - ry*2), (x - rx, y0 - 3*ry/2), (x - rx/2, y0 - ry*2))
+      draw.bezier((), (x + rx, y0 - ry), (x + rx/2, y0 - ry*2), (x + rx, y0 - 3*ry/2))
+    }
+  )
+  draw.content(
+    (x, y),
+    p.display-name,
+    anchor: if bottom {"north"} else {"south"}
+  )
+}
+
+#let _render-collections(x, y, p, m, bottom) = {
+  let w = m.width / 1pt
+  let h = m.height / 1pt
+  let dx = COLLECTIONS-DX
+  let dy = COLLECTIONS-DY
+  let total-w = w + PAR-PAD.last() * 2 / 1pt + calc.abs(dx)
+  let total-h = h + PAR-PAD.first() * 2 / 1pt + calc.abs(dy)
+
+  let x0 = x - total-w / 2
+  let x1 = x0 + calc.abs(dx)
+  let x3 = x0 + total-w
+  let x2 = x3 - calc.abs(dx)
+  
+  let y0 = if bottom {y} else {y + total-h}
+  let y1 = y0 - calc.abs(dy)
+  let y3 = y0 - total-h
+  let y2 = y3 + calc.abs(dy)
+
+  let r1 = (x1, y0, x3, y2)
+  let r2 = (x0, y1, x2, y3)
+
+  if dx < 0 {
+    r1.at(0) = x0
+    r1.at(2) = x2
+    r2.at(0) = x1
+    r2.at(2) = x3
+  }
+
+  if dy < 0 {
+    r1.at(1) = y1
+    r1.at(3) = y3
+    r2.at(1) = y0
+    r2.at(3) = y2
+  }
+  draw.rect(
+    (r1.at(0), r1.at(1)),
+    (r1.at(2), r1.at(3)),
+    fill: p.color,
+    stroke: black + .5pt
+  )
+  draw.rect(
+    (r2.at(0), r2.at(1)),
+    (r2.at(2), r2.at(3)),
+    fill: p.color,
+    stroke: black + .5pt
+  )
+  
+  draw.content(
+    ((r2.at(0) + r2.at(2)) / 2, (r2.at(1) + r2.at(3)) / 2),
+    p.display-name,
+    anchor: "center"
+  )
+}
+
+#let _render-queue(x, y, p, m, bottom) = {
+  let w = (m.width + QUEUE-PAD.last() * 2) / 1pt
+  let h = (m.height + QUEUE-PAD.first() * 2) / 1pt
+  let total-h = h
+  let ry = total-h / 2
+  let rx = ry / 2
+  let total-w = w + 3 + 3 * rx
+
+  let x0 = x - total-w / 2
+  let y0 = if bottom {y} else {y + total-h}
+  let y1 = y0 - total-h
+  let x-left = x0 + rx
+  let x-right = x-left + w + rx
+  draw.merge-path(
+    close: true,
+    fill: p.color,
+    stroke: black + .5pt,
+    {
+      draw.bezier((x-right, y0), (x-right + rx, y0 - ry), (x-right + rx/2, y0), (x-right + rx, y0 - ry/2))
+      draw.bezier((), (x-right, y1), (x-right + rx, y1 + ry/2), (x-right + rx/2, y1))
+      draw.line((), (x-left, y1))
+      draw.bezier((), (x-left - rx, y0 - ry), (x-left - rx/2, y1), (x-left - rx, y1 + ry/2))
+      draw.bezier((), (x-left, y0), (x-left - rx, y0 - ry/2), (x-left - rx/2, y0))
+    }
+  )
+  draw.merge-path(
+    stroke: black + .5pt,
+    {
+      draw.bezier((x-right, y0), (x-right - rx, y0 - ry), (x-right - rx/2, y0), (x-right - rx, y0 - ry/2))
+      draw.bezier((), (x-right, y1), (x-right - rx, y1 + ry/2), (x-right - rx/2, y1))
+    }
+  )
+  draw.content(
+    ((x-left + x-right - rx) / 2, y0 - ry),
+    p.display-name,
+    anchor: "center"
+  )
+}
+
+#let _render-custom(x, y, p, m, bottom) = {
+  let image-m = measure(p.custom-image)
+  let y0 = if bottom {y - m.height / 1pt - SYM-GAP} else {y + m.height / 1pt + image-m.height / 1pt + SYM-GAP}
+  draw.content((x - image-m.width / 2pt, y0), p.custom-image, anchor: "north-west")
+  draw.content(
+    (x, y),
+    p.display-name,
+    anchor: if bottom {"north"} else {"south"}
+  )
+}
+
+#let render(x-pos, p, y: 0, bottom: false) = {
+  let m = measure(box(p.display-name))
+  let func = (
+    participant: _render-participant,
+    actor: _render-actor,
+    boundary: _render-boundary,
+    control: _render-control,
+    entity: _render-entity,
+    database: _render-database,
+    collections: _render-collections,
+    queue: _render-queue,
+    custom: _render-custom,
+  ).at(p.shape)
+  func(x-pos.at(p.i), y, p, m, bottom)
+}

src/renderer.typ

@@ -1,19 +1,36 @@
 #import "@preview/cetz:0.2.2": canvas, draw
+#import "utils.typ": get-participants-i, get-style
+#import "group.typ"
+#import "participant.typ"
+#import participant: PAR-SPECIALS
+#import "sequence.typ"
+#import "separator.typ"
+#import "sync.typ"
+#import "consts.typ": *
+#import "note.typ" as note: get-note-box
 
-#let X-SPACE = 2
+#let DEBUG-INVISIBLE = false
-#let Y-SPACE = 30
-
-#let get-participants-i(participants) = {
-  let pars-i = (:)
-  for (i, p) in participants.enumerate() {
-    pars-i.insert(p.name, i)
-  }
-  return pars-i
-}
 
 #let get-columns-width(participants, elements) = {
+  participants = participants.map(p => {
+    p.insert("lifeline-lvl", 0)
+    p.insert("max-lifelines", 0)
+    p
+  })
   let pars-i = get-participants-i(participants)
   let cells = ()
+
+  // Unwrap syncs
+  let i = 0
+  while i < elements.len() {
+    let elmt = elements.at(i)
+    if elmt.type == "sync" {
+      elements = elements.slice(0, i + 1) + elmt.elmts + elements.slice(i + 1)
+    }
+    i += 1
+  }
+
+  // Compute max lifeline levels
   for elmt in elements {
     if elmt.type == "seq" {
       let com = if elmt.comment == none {""} else {elmt.comment}
@@ -27,82 +44,384 @@
           cell: box(com, inset: 3pt)
         )
       )
+
+      if elmt.disable-src or elmt.destroy-src {
+        let p = participants.at(i1)
+        p.lifeline-lvl -= 1
+        participants.at(i1) = p
+      }
+      if elmt.disable-dst {
+        let p = participants.at(i2)
+        p.lifeline-lvl -= 1
+        participants.at(i2) = p
+      }
+      if elmt.enable-dst {
+        let p = participants.at(i2)
+        p.lifeline-lvl += 1
+        p.max-lifelines = calc.max(p.max-lifelines, p.lifeline-lvl)
+        participants.at(i2) = p
+      }
+    } else if elmt.type == "evt" {
+      let par-name = elmt.participant
+      let i = pars-i.at(par-name)
+      let par = participants.at(i)
+      if elmt.event == "disable" or elmt.event == "destroy" {
+        par.lifeline-lvl -= 1
+      
+      } else if elmt.event == "enable" {
+        par.lifeline-lvl += 1
+        par.max-lifelines = calc.max(par.max-lifelines, par.lifeline-lvl)
+      }
+      participants.at(i) = par
+    
+    } else if elmt.type == "note" {
+      let (p1, p2) = (none, none)
+      let cell = none
+      if elmt.side == "left" {
+        p1 = "["
+        p2 = elmt.pos
+        cell = get-note-box(elmt)
+      } else if elmt.side == "right" {
+        p1 = elmt.pos
+        p2 = "]"
+        cell = get-note-box(elmt)
+      } else if elmt.side == "over" {
+        if elmt.aligned-with != none {
+          let box1 = get-note-box(elmt)
+          let box2 = get-note-box(elmt.aligned-with)
+          let m1 = measure(box1)
+          let m2 = measure(box2)
+          cell = box(width: (m1.width + m2.width) / 2, height: calc.max(m1.height, m2.height))
+          p1 = elmt.pos
+          p2 = elmt.aligned-with.pos
+        }
+      }
+
+      if p1 != none and p2 != none and cell != none {
+        let i1 = pars-i.at(p1)
+        let i2 = pars-i.at(p2)
+        cells.push(
+          (
+            elmt: elmt,
+            i1: calc.min(i1, i2),
+            i2: calc.max(i1, i2),
+            cell: cell
+          )
+        )
+      }
     }
   }
 
-  let widths = participants.slice(0, -1).map(_ => 0)
+  // Compute column widths
+  // Compute minimum widths for participant names and shapes
+  let widths = ()
+  for i in range(participants.len() - 1) {
+    let p1 = participants.at(i)
+    let p2 = participants.at(i + 1)
+    let m1 = participant.get-size(p1)
+    let m2 = participant.get-size(p2)
+    let w1 = m1.width
+    let w2 = m2.width
+    widths.push(w1 / 2pt + w2 / 2pt + PAR-SPACE)
+  }
+
+  // Compute minimum width for over notes
+  for n in elements.filter(e => (e.type == "note" and
+                                 e.side == "over" and 
+                                 type(e.pos) == str)) {
+    
+    let m = note.get-size(n)
+    let i = pars-i.at(n.pos)
+
+    if i < widths.len() {
+      widths.at(i) = calc.max(
+        widths.at(i),
+        m.width / 2 + NOTE-GAP
+      )
+    }
+    if i > 0 {
+      widths.at(i - 1) = calc.max(
+        widths.at(i - 1),
+        m.width / 2 + NOTE-GAP
+      )
+    }
+  }
+
+  // Compute minimum width for simple sequences (spanning 1 column)
   for cell in cells.filter(c => c.i2 - c.i1 == 1) {
     let m = measure(cell.cell)
     widths.at(cell.i1) = calc.max(
       widths.at(cell.i1),
-      m.width / 1pt
+      m.width / 1pt + COMMENT-PAD
     )
   }
+
+  // Compute minimum width for self sequences
+  for cell in cells.filter(c => c.elmt.type == "seq" and c.i1 == c.i2) {
+    let m = measure(cell.cell)
+    let i = cell.i1
+    if cell.elmt.flip {
+      i -= 1
+    }
+    if 0 <= i and i < widths.len() {
+      widths.at(i) = calc.max(
+        widths.at(i),
+        m.width / 1pt + COMMENT-PAD
+      )
+    }
+  }
+
+  // Compute remaining widths for longer sequences (spanning multiple columns)
+  let multicol-cells = cells.filter(c => c.i2 - c.i1 > 1)
+  multicol-cells = multicol-cells.sorted(key: c => {
+    c.i1 * 1000 + c.i2
+  })
+  for cell in multicol-cells {
+    let m = measure(cell.cell)
+    widths.at(cell.i2 - 1) = calc.max(
+      widths.at(cell.i2 - 1),
+      m.width / 1pt + COMMENT-PAD - widths.slice(cell.i1, cell.i2 - 1).sum()
+    )
+  }
+
+  // Add lifeline widths
+  for (i, w) in widths.enumerate() {
+    let p1 = participants.at(i)
+    let p2 = participants.at(i + 1)
+    let w = w + p1.max-lifelines * LIFELINE-W / 2
+    if p2.max-lifelines != 0 {
+      w += LIFELINE-W / 2
+    }
+    widths.at(i) = w
+  }
   return widths
 }
 
 #let render(participants, elements) = context canvas(length: 1pt, {
+  let shapes = ()
   let pars-i = get-participants-i(participants)
 
   let widths = get-columns-width(participants, elements)
 
+  // Compute each column's X position
   let x-pos = (0,)
   for width in widths {
     x-pos.push(x-pos.last() + width)
   }
 
-  // Draw participants
+  let draw-seq = sequence.render.with(pars-i, x-pos, participants)
-  for (i, p) in participants.enumerate() {
+  let draw-group = group.render.with()
-    draw.content(
+  let draw-sep = separator.render.with(x-pos)
-      (x-pos.at(i), 0),
+  let draw-par = participant.render.with(x-pos)
-      p.display-name,
+  let draw-note = note.render.with(pars-i, x-pos)
-      name: p.name,
+  let draw-sync = sync.render.with(pars-i, x-pos, participants)
-      frame: "rect",
+  
-      padding: (5pt, 3pt),
+  // Draw participants (start)
-      anchor: "south"
+  for p in participants {
-    )
+    if p.from-start and not p.invisible and p.show-top {
+      shapes += draw-par(p)
+    }
   }
 
-  let y = -Y-SPACE
+  let y = 0
-  // Draw sequences
+  let groups = ()
+  let lifelines = participants.map(_ => (
+    level: 0,
+    lines: ()
+  ))
+
+  // Draw elemnts
   for elmt in elements {
+    // Sequences
     if elmt.type == "seq" {
-      let x1 = x-pos.at(pars-i.at(elmt.p1))
+      let shps
-      let x2 = x-pos.at(pars-i.at(elmt.p2))
+      (y, lifelines, shps) = draw-seq(elmt, y, lifelines)
-      draw.line(
+      shapes += shps
-        (x1, y),
+
-        (x2, y),
+    // Groups (start) -> reserve space for labels + store position
-        mark: (end: "straight")
+    } else if elmt.type == "grp" {
+      y -= Y-SPACE
+      let m = measure(
+        box(
+          elmt.name,
+          inset: (left: 5pt, right: 5pt, top: 3pt, bottom: 3pt),
+        )
       )
-      if elmt.comment != none {
+      groups = groups.map(g => {
+        if g.at(1).min-i == elmt.min-i { g.at(2) += 1 }
+        if g.at(1).max-i == elmt.max-i { g.at(3) += 1 }
+        g
+      })
+      groups.push((y, elmt, 0, 0))
+      y -= m.height / 1pt
+    
+    // Groups (end) -> actual drawing
+    } else if elmt.type == "grp-end" {
+      y -= Y-SPACE
+      let (start-y, group, start-lvl, end-lvl) = groups.pop()
+      let x0 = x-pos.at(group.min-i) - start-lvl * 10 - 20
+      let x1 = x-pos.at(group.max-i) + end-lvl * 10 + 20
+      shapes += draw-group(x0, x1, start-y, y, group)
+
+    // Separator
+    } else if elmt.type == "sep" {
+      let shps
+      (y, shps) = draw-sep(elmt, y)
+      shapes += shps
+    
+    // Gap
+    } else if elmt.type == "gap" {
+      y -= elmt.size
+    
+    // Event
+    } else if elmt.type == "evt" {
+      let par-name = elmt.participant
+      let i = pars-i.at(par-name)
+      let par = participants.at(i)
+      let line = lifelines.at(i)
+      if elmt.event == "disable" {
+        line.level -= 1
+        line.lines.push(("disable", y))
+      
+      } else if elmt.event == "destroy" {
+        line.lines.push(("destroy", y))
+      
+      } else if elmt.event == "enable" {
+        line.level += 1
+        line.lines.push(("enable", y, elmt.lifeline-style))
+      
+      } else if elmt.event == "create" {
+        y -= CREATE-OFFSET
+        shapes += participant.render(x-pos, par, y: y)
+        line.lines.push(("create", y))
+      }
+      lifelines.at(i) = line
+    
+    // Note
+    } else if elmt.type == "note" {
+      if not elmt.linked {
+        if not elmt.aligned {
+          y -= Y-SPACE
+        }
+        let shps
+        (y, shps) = draw-note(elmt, y, lifelines)
+        shapes += shps
+      }
+
+    // Synched sequences
+    } else if elmt.type == "sync" {
+      let shps
+      (y, lifelines, shps) = draw-sync(elmt, y, lifelines)
+      shapes += shps
+    }
+  }
+
+  y -= Y-SPACE
+
+  // Draw vertical lines + lifelines + end participants
+  shapes += draw.on-layer(-1, {
+    if DEBUG-INVISIBLE {
+      for p in participants.filter(p => p.invisible) {
+        let color = if p.name.starts-with("?") {green} else if p.name.ends-with("?") {red} else {blue}
+        let x = x-pos.at(p.i)
+        draw.line(
+          (x, 0),
+          (x, y),
+          stroke: (paint: color, dash: "dotted")
+        )
         draw.content(
-          (calc.min(x1, x2), y),
+          (x, 0),
-          elmt.comment,
+          p.display-name,
-          anchor: "south-west",
+          anchor: "west",
-          padding: 3pt
+          angle: 90deg
         )
       }
-      y -= Y-SPACE
     }
-  }
     
-  // Draw vertical lines + end participants
+    for p in participants.filter(p => not p.invisible) {
-  draw.on-layer(-1, {
+      let x = x-pos.at(p.i)
-    for (i, p) in participants.enumerate() {
+
-      let x = x-pos.at(i)
+      // Draw vertical line
+      let last-y = 0
+
+      let rects = ()
+      let destructions = ()
+      let lines = ()
+
+      // Compute lifeline rectangles + destruction positions
+      for line in lifelines.at(p.i).lines {
+        let event = line.first()
+        if event == "create" {
+          last-y = line.at(1)
+
+        } else if event == "enable" {
+          if lines.len() == 0 {
+            draw.line(
+              (x, last-y),
+              (x, line.at(1)),
+              stroke: (
+                dash: "dashed",
+                paint: gray.darken(40%),
+                thickness: .5pt
+              )
+            )
+          }
+          lines.push(line)
+        
+        } else if event == "disable" or event == "destroy" {
+          let lvl = 0
+          if lines.len() != 0 {
+            let l = lines.pop()
+            lvl = lines.len()
+            rects.push((
+              x + lvl * LIFELINE-W / 2,
+              l.at(1),
+              line.at(1),
+              l.at(2)
+            ))
+            last-y = line.at(1)
+          }
+
+          if event == "destroy" {
+            destructions.push((x + lvl * LIFELINE-W / 2, line.at(1)))
+          }
+        }
+      }
+
       draw.line(
-        (x, 0),
+        (x, last-y),
         (x, y),
-        stroke: (dash: "dashed", paint: gray.darken(40%))
+        stroke: (
-      )
+          dash: "dashed",
-      draw.content(
+          paint: gray.darken(40%),
-        (x, y),
+          thickness: .5pt
-        p.display-name,
+        )
-        name: p.name,
-        frame: "rect",
-        padding: (5pt, 3pt),
-        anchor: "north"
       )
+
+      // Draw lifeline rectangles (reverse for bottom to top)
+      for rect in rects.rev() {
+        let (cx, y0, y1, style) = rect
+        let style = get-style("lifeline", style)
+        draw.rect(
+          (cx - LIFELINE-W / 2, y0),
+          (cx + LIFELINE-W / 2, y1),
+          ..style
+        )
+      }
+
+      // Draw lifeline destructions
+      for dest in destructions {
+        let (cx, cy) = dest
+        draw.line((cx - 8, cy - 8), (cx + 8, cy + 8), stroke: COL-DESTRUCTION + 2pt)
+        draw.line((cx - 8, cy + 8), (cx + 8, cy - 8), stroke: COL-DESTRUCTION + 2pt)
+      }
+
+      // Draw participants (end)
+      if p.show-bottom {
+        draw-par(p, y: y, bottom: true)
+      }
     }
   })
+
+  shapes
 })

src/separator.typ

@@ -0,0 +1,55 @@
+#import "@preview/cetz:0.2.2": draw
+#import "consts.typ": *
+
+#let _sep(name) = {
+  return ((
+    type: "sep",
+    name: name
+  ),)
+}
+
+#let render(x-pos, elmt, y) = {
+  let shapes = ()
+  y -= Y-SPACE
+
+  let x0 = x-pos.first() - 20
+  let x1 = x-pos.last() + 20
+  let m = measure(
+    box(
+      elmt.name,
+      inset: (left: 3pt, right: 3pt, top: 5pt, bottom: 5pt)
+    )
+  )
+  let w = m.width / 1pt
+  let h = m.height / 1pt
+  let cx = (x0 + x1) / 2
+  let xl = cx - w / 2
+  let xr = cx + w / 2
+
+  y -= h / 2
+  shapes += draw.rect(
+    (x0, y),
+    (x1, y - 3),
+    stroke: none,
+    fill: white
+  )
+  shapes += draw.line((x0, y), (x1, y))
+  //shapes += draw.line((x0, y), (xl, y))
+  //shapes += draw.line((xr, y), (x1, y))
+  y -= 3
+  shapes += draw.line((x0, y), (x1, y))
+  //shapes += draw.line((x0, y), (xl, y))
+  //shapes += draw.line((xr, y), (x1, y))
+  shapes += draw.content(
+    ((x0 + x1) / 2, y + 1.5),
+    elmt.name,
+    anchor: "center",
+    padding: (5pt, 3pt),
+    frame: "rect",
+    fill: COL-SEP-NAME
+  )
+  y -= h / 2
+
+  let r = (y, shapes)
+  return r
+}

src/sequence.typ

@@ -0,0 +1,370 @@
+#import "@preview/cetz:0.2.2": draw, vector
+#import "consts.typ": *
+#import "participant.typ"
+#import "note.typ"
+
+#let get-arrow-marks(sym, color) = {
+  if type(sym) == array {
+    return sym.map(s => get-arrow-marks(s, color))
+  }
+  (
+    "": none,
+    ">": (symbol: ">", fill: color),
+    ">>": (symbol: "straight"),
+    "\\": (symbol: ">", fill: color, harpoon: true, flip: true),
+    "\\\\": (symbol: "straight", harpoon: true, flip: true),
+    "/": (symbol: ">", fill: color, harpoon: true),
+    "//": (symbol: "straight", harpoon: true),
+    "x": none,
+    "o": none,
+  ).at(sym)
+}
+
+#let reverse-arrow-mark(mark) = {
+  if type(mark) == array {
+    return mark.map(m => reverse-arrow-mark(m))
+  }
+  let mark2 = mark
+  if type(mark) == dictionary and mark.at("harpoon", default: false) {
+    let flipped = mark.at("flip", default: false)
+    mark2.insert("flip", not flipped)
+  }
+  return mark2
+}
+
+#let is-tip-of-type(type_, tip) = {
+  if type(tip) == str and tip == type_ {
+    return true
+  }
+  if type(tip) == array and tip.contains(type_) {
+    return true
+  }
+  return false
+}
+#let is-circle-tip = is-tip-of-type.with("o")
+#let is-cross-tip = is-tip-of-type.with("x")
+
+#let _seq(
+  p1,
+  p2,
+  comment: none,
+  comment-align: "left",
+  dashed: false,
+  start-tip: "",
+  end-tip: ">",
+  color: black,
+  flip: false,
+  enable-dst: false,
+  create-dst: false,
+  disable-dst: false,
+  destroy-dst: false,
+  disable-src: false,
+  destroy-src: false,
+  lifeline-style: auto,
+  slant: none
+) = {
+  return ((
+    type: "seq",
+    p1: p1,
+    p2: p2,
+    comment: comment,
+    comment-align: comment-align,
+    dashed: dashed,
+    start-tip: start-tip,
+    end-tip: end-tip,
+    color: color,
+    flip: flip,
+    enable-dst: enable-dst,
+    create-dst: create-dst,
+    disable-dst: disable-dst,
+    destroy-dst: destroy-dst,
+    disable-src: disable-src,
+    destroy-src: destroy-src,
+    lifeline-style: lifeline-style,
+    slant: slant
+  ),)
+}
+
+#let render(pars-i, x-pos, participants, elmt, y, lifelines) = {
+  let shapes = ()
+
+  y -= Y-SPACE
+
+  let h = 0
+  // Reserve space for comment
+  if elmt.comment != none {
+    h = calc.max(h, measure(box(elmt.comment)).height / 1pt + 6)
+  }
+  if "linked-note" in elmt {
+    h = calc.max(h, note.get-size(elmt.linked-note).height / 2)
+  }
+  y -= h
+
+  let i1 = pars-i.at(elmt.p1)
+  let i2 = pars-i.at(elmt.p2)
+
+  let start-info = (
+    i: i1,
+    x: x-pos.at(i1),
+    y: y,
+    ll-lvl: lifelines.at(i1).level * LIFELINE-W / 2
+  )
+  let end-info = (
+    i: i2,
+    x: x-pos.at(i2),
+    y: y,
+    ll-lvl: lifelines.at(i2).level * LIFELINE-W / 2
+  )
+  let slant = if elmt.slant == auto {
+    DEFAULT-SLANT
+  } else if elmt.slant != none {
+    elmt.slant
+  } else {
+    0
+  }
+  end-info.y -= slant
+  if elmt.p1 == elmt.p2 {
+    end-info.y -= 10
+  }
+
+  if elmt.disable-src {
+    let src-line = lifelines.at(i1)
+    src-line.level -= 1
+    src-line.lines.push(("disable", start-info.y))
+    lifelines.at(i1) = src-line
+  }
+  if elmt.destroy-src {
+    let src-line = lifelines.at(i1)
+    src-line.lines.push(("destroy", start-info.y))
+    lifelines.at(i1) = src-line
+  }
+  if elmt.disable-dst {
+    let dst-line = lifelines.at(i2)
+    dst-line.level -= 1
+    dst-line.lines.push(("disable", end-info.y))
+    lifelines.at(i2) = dst-line
+  }
+  if elmt.destroy-dst {
+    let dst-line = lifelines.at(i2)
+    dst-line.lines.push(("destroy", end-info.y))
+    lifelines.at(i2) = dst-line
+  }
+  if elmt.enable-dst {
+    let dst-line = lifelines.at(i2)
+    dst-line.level += 1
+    lifelines.at(i2) = dst-line
+  }
+  if elmt.create-dst {
+    let par = participants.at(i2)
+    let m = measure(box(par.display-name))
+    let f = if i1 > i2 {-1} else {1}
+    end-info.x -= (m.width + PAR-PAD.last() * 2) / 2pt * f
+    shapes += participant.render(x-pos, par, y: end-info.y - CREATE-OFFSET)
+  }
+
+  end-info.ll-lvl = lifelines.at(i2).level * LIFELINE-W / 2
+
+  // Compute left/right position at start/end
+  start-info.insert("lx", start-info.x)
+  if start-info.ll-lvl != 0 { start-info.lx -= LIFELINE-W / 2 }
+  end-info.insert("lx", end-info.x)
+  if end-info.ll-lvl != 0 { end-info.lx -= LIFELINE-W / 2 }
+
+  start-info.insert("rx", start-info.x + start-info.ll-lvl)
+  end-info.insert("rx", end-info.x + end-info.ll-lvl)
+
+  // Choose correct points to link
+  let x1 = start-info.rx
+  let x2 = end-info.lx
+
+  if (start-info.i > end-info.i) {
+    x1 = start-info.lx
+    x2 = end-info.rx
+  }
+
+  let style = (
+    mark: (
+      start: get-arrow-marks(elmt.start-tip, elmt.color),
+      end: get-arrow-marks(elmt.end-tip, elmt.color),
+      scale: 1.2
+    ),
+    stroke: (
+      dash: if elmt.dashed {(2pt,2pt)} else {"solid"},
+      paint: elmt.color,
+      thickness: .5pt
+    )
+  )
+
+  let y0 = start-info.y
+  if "linked-note" in elmt {
+    let shps = note.render(pars-i, x-pos, elmt.linked-note, start-info.y, lifelines).last()
+    shapes += shps
+  }
+
+  let flip-mark = end-info.i <= start-info.i
+  if elmt.flip {
+    flip-mark = not flip-mark
+  }
+  if flip-mark {
+    style.mark.end = reverse-arrow-mark(style.mark.end)
+  }
+
+  let pts
+  let comment-pt
+  let comment-anchor
+  let comment-angle = 0deg
+
+  if elmt.p1 == elmt.p2 {
+    if elmt.flip {
+      x1 = start-info.lx
+    } else {
+      x2 = end-info.rx
+    }
+
+    let x-mid = if elmt.flip {
+      calc.min(x1, x2) - 20
+    } else {
+      calc.max(x1, x2) + 20
+    }
+
+    pts = (
+      (x1, start-info.y),
+      (x-mid, start-info.y),
+      (x-mid, end-info.y),
+      (x2, end-info.y)
+    )
+
+    if elmt.comment != none {
+      comment-anchor = (
+        start: if x-mid < x1 {"south-east"} else {"south-west"},
+        end: if x-mid < x1 {"south-west"} else {"south-east"},
+        left: "south-west",
+        right: "south-east",
+        center: "south",
+      ).at(elmt.comment-align)
+
+      comment-pt = (
+        start: pts.first(),
+        end: pts.at(1),
+        left: if x-mid < x1 {pts.at(1)} else {pts.first()},
+        right: if x-mid < x1 {pts.first()} else {pts.at(1)},
+        center: (pts.first(), 50%, pts.at(1))
+      ).at(elmt.comment-align)
+    }
+
+  } else {
+    pts = (
+      (x1, start-info.y),
+      (x2, end-info.y)
+    )
+
+    if elmt.comment != none {
+      let start-pt = pts.first()
+      let end-pt = pts.last()
+      if elmt.start-tip != "" {
+        start-pt = (pts.first(), COMMENT-PAD, pts.last())
+      }
+      if elmt.end-tip != "" {
+        end-pt = (pts.last(), COMMENT-PAD, pts.first())
+      }
+
+      comment-pt = (
+        start: start-pt,
+        end: end-pt,
+        left: if x2 < x1 {end-pt} else {start-pt},
+        right: if x2 < x1 {start-pt} else {end-pt},
+        center: (start-pt, 50%, end-pt)
+      ).at(elmt.comment-align)
+
+      comment-anchor = (
+        start: if x2 < x1 {"south-east"} else {"south-west"},
+        end: if x2 < x1 {"south-west"} else {"south-east"},
+        left: "south-west",
+        right: "south-east",
+        center: "south",
+      ).at(elmt.comment-align)
+    }
+
+    let (p1, p2) = pts
+    if x2 < x1 {
+      (p1, p2) = (p2, p1)
+    }
+    comment-angle = vector.angle2(p1, p2)
+  }
+
+  // Start circle tip
+  if is-circle-tip(elmt.start-tip) {
+    shapes += draw.circle(pts.first(), radius: CIRCLE-TIP-RADIUS, stroke: elmt.color, fill: none, name: "_circle-start-tip")
+    pts.at(0) = "_circle-start-tip"
+  
+  // Start cross tip
+  } else if is-cross-tip(elmt.start-tip) {
+    let size = CROSS-TIP-SIZE
+    let cross-pt = (pts.first(), size * 2, pts.at(1))
+    shapes += draw.line(
+      (rel: (-size, -size), to: cross-pt),
+      (rel: (size, size), to: cross-pt),
+      stroke: elmt.color + 1.5pt
+    )
+    shapes += draw.line(
+      (rel: (-size, size), to: cross-pt),
+      (rel: (size, -size), to: cross-pt),
+      stroke: elmt.color + 1.5pt
+    )
+    pts.at(0) = cross-pt
+  }
+
+  // End circle tip
+  if is-circle-tip(elmt.end-tip) {
+    shapes += draw.circle(pts.last(), radius: 3, stroke: elmt.color, fill: none, name: "_circle-end-tip")
+    pts.at(pts.len() - 1) = "_circle-end-tip"
+  
+  // End cross tip
+  } else if is-cross-tip(elmt.end-tip) {
+    let size = CROSS-TIP-SIZE
+    let cross-pt = (pts.last(), size * 2, pts.at(pts.len() - 2))
+    shapes += draw.line(
+      (rel: (-size, -size), to: cross-pt),
+      (rel: (size, size), to: cross-pt),
+      stroke: elmt.color + 1.5pt
+    )
+    shapes += draw.line(
+      (rel: (-size, size), to: cross-pt),
+      (rel: (size, -size), to: cross-pt),
+      stroke: elmt.color + 1.5pt
+    )
+    pts.at(pts.len() - 1) = cross-pt
+  }
+
+  shapes += draw.line(..pts, ..style)
+
+  if elmt.comment != none {
+    shapes += draw.content(
+      comment-pt,
+      elmt.comment,
+      anchor: comment-anchor,
+      angle: comment-angle,
+      padding: 3pt
+    )
+  }
+
+  if elmt.enable-dst {
+    let dst-line = lifelines.at(i2)
+    dst-line.lines.push(("enable", end-info.y, elmt.lifeline-style))
+    lifelines.at(i2) = dst-line
+  }
+  if elmt.create-dst {
+    end-info.y -= CREATE-OFFSET
+    let dst-line = lifelines.at(i2)
+    dst-line.lines.push(("create", end-info.y))
+    lifelines.at(i2) = dst-line
+  }
+
+  if "linked-note" in elmt {
+    let m = note.get-size(elmt.linked-note)
+    end-info.y = calc.min(end-info.y, y0 - m.height / 2)
+  }
+
+  let r = (end-info.y, lifelines, shapes)
+  return r
+}

src/sync.typ

@@ -0,0 +1,27 @@
+#import "sequence.typ"
+
+#let _sync(elmts) = {
+  return ((
+    type: "sync",
+    elmts: elmts
+  ),)
+}
+
+#let render(pars-i, x-pos, participants, elmt, y, lifelines) = {
+  let draw-seq = sequence.render.with(pars-i, x-pos, participants)
+
+  let shapes = ()
+
+  let end-y = y
+
+  for e in elmt.elmts {
+    let yi
+    let shps
+    (yi, lifelines, shps) = draw-seq(e, y, lifelines)
+    shapes += shps
+    end-y = calc.min(end-y, yi)
+  }
+
+  let r = (end-y, lifelines, shapes)
+  return r
+}

src/utils.typ

@@ -0,0 +1,70 @@
+#let get-participants-i(participants) = {
+  let pars-i = (:)
+  for (i, p) in participants.enumerate() {
+    pars-i.insert(p.name, i)
+  }
+  return pars-i
+}
+
+#let get-group-span(participants, group) = {
+  let min-i = participants.len() - 1
+  let max-i = 0
+  let pars-i = get-participants-i(participants)
+
+  for elmt in group.elmts {
+    if elmt.type == "seq" {
+      let i1 = pars-i.at(elmt.p1)
+      let i2 = pars-i.at(elmt.p2)
+      min-i = calc.min(min-i, i1, i2)
+      max-i = calc.max(max-i, i1, i2)
+    } else if elmt.type == "grp" {
+      let (i0, i1) = get-group-span(participants, elmt)
+      min-i = calc.min(min-i, i0)
+      max-i = calc.max(max-i, i1)
+    } else if elmt.type == "sync" {
+      let (i0, i1) = get-group-span(participants, elmt)
+      min-i = calc.min(min-i, i0)
+      max-i = calc.max(max-i, i1)
+    }
+  }
+  return (min-i, max-i)
+}
+
+#let get-style(base-name, mods) = {
+  let style = if base-name == "lifeline" {(
+    fill: white,
+    stroke: black + 1pt
+  )}
+
+  if mods == auto {
+    return style
+  }
+  if type(mods) == dictionary {
+    return style + mods
+  }
+
+  panic("Invalid type for parameter mods, expected auto or dictionary, got " + str(type(mods)))
+}
+
+#let fit-canvas(canvas, width: auto) = layout(size => {
+  let m = measure(canvas)
+  let w = m.width
+  let h = m.height
+  let r = if w == 0pt {0} else {
+    if width == auto {1}
+    else if type(width) == length {
+      width / w
+    } else {
+      size.width * width / w
+    }
+  }
+  let new-w = w * r
+  let new-h = h * r
+  r *= 100%
+  
+  box(
+    width: new-w,
+    height: new-h,
+    scale(x: r, y: r, reflow: true, canvas)
+  )
+})

typst.toml

@@ -11,4 +11,4 @@ categories = ["visualization"]
 license = "Apache-2.0"
 description = "A package to draw sequence diagrams with CeTZ"
 keywords = ["sequence", "diagram", "plantuml"]
-exclude = [ "/gallery/*" ]
+exclude = [ "/gallery/*", "/gallery.bash", "/TODO.md" ]